JP7388583B2 - hot water production system - Google Patents

Description

The present invention relates to a hot water production system.

Conventionally, hot water production systems are known. For example, Patent Document 1 discloses a system that uses a heat pump to produce hot water in order to wash or sterilize a work such as food with hot water.

Japanese Patent Application Publication No. 2009-133522

Currently, many factories and business establishments are moving forward with ``decarbonization'' efforts to move away from fossil fuels, with the aim of reducing emissions of _CO2 , a typical greenhouse gas. Therefore, as shown in Patent Document 1, systems using heat pumps are increasingly being adopted as systems for producing hot water. However, with heat pumps, if the hot water outlet temperature is low, the COP (energy consumption efficiency) is high and the effect of reducing _CO2 emissions is high, but when the hot water outlet temperature is raised and used, the COP becomes low and the _CO2 emissions are reduced. It has the characteristic that the reduction effect also decreases. Moreover, when using the hot water at a higher temperature, the COP is low, so the running cost is also high.

The present invention has been made in view of the above problems, and its purpose is to provide a hot water production system that is highly effective in reducing _CO2 emissions and can reduce running costs even when the hot water temperature is increased. It's about doing.

The present invention provides a first heating means (for example, the first heating means 2) that heats water to a target hot water supply temperature while circulating water to a heat pump water heater (for example, the water heater of the heat pump water heater system 10); The water heated to the target hot water supply temperature by the first heating means is directly exchanged with steam generated by a steam boiler (for example, the steam boiler device 30), so that the water temperature is set higher than the target hot water supply temperature. A second heating means (for example, second heating means 3) that raises the temperature to a target tapping temperature, and a control means that controls the first heating means and the second heating means, the control means The present invention relates to a hot water production system that adjusts the output sharing between the water heater and the steam boiler according to the set target hot water temperature.

Further, the second heating means includes a steam header (e.g., steam header 51) that collects the steam generated in the steam boiler, and a heating steam supply valve that adjusts the amount of steam supplied from the steam header. (for example, a steam supply valve for temperature increase 54), and the control means includes a boiler control unit that controls the steam boiler so that the header pressure of the steam header becomes the target steam pressure, and 2. It is preferable to include a steam supply control section that controls the temperature raising steam supply valve so that the hot water discharged from the heating means reaches the set target hot water discharge temperature.

The first heating means also includes a first hot water tank (for example, a first hot water tank 40 ), a circulation line that circulates water between the water heater and the first hot water tank, and a hot water temperature sensor that detects the temperature of hot water generated by the water heater, and the second heating means is provided in a heating steam supply line (e.g., heating steam supply line L2) that supplies steam generated by the steam boiler to hot water generated in the water heater, and in the heating steam supply line L2. and a second temperature sensor (for example, second temperature sensor 241) that detects the temperature of the hot water after supplying the steam, The control means controls the water heater so that the temperature detected by the hot water temperature sensor becomes the target hot water temperature, and controls the heating water heater so that the temperature detected by the second temperature sensor becomes the target hot water temperature. It is preferable to control the opening degree of the steam valve.

Further, the second heating means includes a second hot water tank (for example, a second hot water tank 240) to which hot water is supplied from the first hot water tank, and the temperature raising steam supply line is connected to the second hot water tank. It is preferable that steam generated by the steam boiler is supplied to the tank, and that the second temperature sensor detects the temperature of hot water in the second hot water tank.

Further, the first heating means includes a first temperature sensor that detects the temperature of hot water in the first hot water tank, and the control means controls the circulation line based on the temperature detected by the first temperature sensor. It is preferable to switch between running and stopping the circulation of water through the .

The first heating means also includes a first water level sensor (for example, the first water level sensor 42) that detects the water level in the first hot water tank, and a make-up water line (for example, the first water level sensor 42) that supplies water to the first hot water tank. For example, the control means includes a make-up water line L5) and a make-up water valve (for example, make-up water valve 62) provided in the make-up water line, and the control means is configured such that the detected water level of the first water level sensor is higher than the set water level. When the water drops below the water level, it is preferable to open the make-up water valve.

Further, a preheating heat exchanger (for example, preheating heat exchanger 75) that indirectly exchanges heat between water and steam flowing through the make-up water line, and a preheating heat exchanger that uses steam generated in the steam boiler in the preheating heat exchanger a preheating steam supply line (e.g., preheating steam supply line L10), and a preheating steam supply valve (for example, preheating steam supply valve 76) provided in the preheating steam supply line, It is preferable that the control means opens the preheating steam supply valve when opening the make-up water valve.

Also, a hot water pump (e.g., hot water pump 243) provided in a hot water delivery line (e.g., hot water delivery line 22) connecting the first hot water tank and the second hot water tank, and a water level of the second hot water tank. and a second water level sensor (for example, second water level sensor 242) that detects the water level, and the control means preferably drives the hot water pump when the detected water level of the second water level sensor falls below a set water level. .

Further, the first heating means includes a first temperature sensor (for example, the first temperature sensor 41) that detects the temperature of the hot water in the first hot water tank, and the first heating means includes a plurality of including a water heater (for example, water heaters 11, 12, 13), a plurality of temperature thresholds are set in the first hot water tank for changing the number of operating water heaters, and the control means When the temperature in the first hot water tank decreases, the number of water heaters in operation is increased by one each time the temperature detected by the first temperature sensor falls below the temperature threshold by one. When the temperature in the hot water tank increases, it is preferable to perform number control in which the number of operating water heaters is decreased by one each time the temperature detected by the first temperature sensor exceeds the temperature threshold by one step.

Further, a water supply tank (for example, water supply tank 60) that stores water to be supplied to the water heater and/or supply water to be supplied to the steam boiler, and a water supply tank (e.g., water supply tank 60) that stores water to be supplied to the water heater and/or water supply to the steam boiler, and a water supply tank that stores the water to be circulated and heated in the water heater in the first hot water tank. Alternatively, it is preferable to include a switching means (for example, switching means 290) for switching to the water stored in the water supply tank.

Further, the first heating means includes a first temperature sensor (for example, the first temperature sensor 41) that detects the temperature of the hot water in the first hot water tank, and the first heating means includes a plurality of The first hot water tank includes a water heater (for example, water heaters 11, 12, and 13), and a plurality of temperature thresholds for changing the number of connected water heaters is set in the first hot water tank. When the temperature in the first hot water tank decreases, each time the temperature detected by the first temperature sensor falls below the temperature threshold by one step, the number of water heaters connected to the first hot water tank is increased by one, and at the same time, The switching means is controlled to reduce the number of water heaters connected to the water supply tank one by one, and when the temperature in the first hot water tank increases, the temperature detected by the first temperature sensor is lower than the temperature threshold. The switching means is controlled to decrease the number of water heaters connected to the first hot water tank by one each time the temperature increases by one step, and simultaneously increase the number of water heaters connected to the water supply tank by one. It is preferable.

The control means also includes a third temperature sensor that detects the temperature of the water stored in the water supply tank, and when the temperature detected by the third temperature sensor reaches a heating stop temperature, the control means controls the hot water being supplied to the water supply tank. Preferably, the device is stopped.

Further, the present invention provides a first heating step of heating water to a target hot water temperature while circulating it in a heat pump water heater (for example, the water heater of the heat pump water heating system 10); A first step in which the water heated to the target hot water supply temperature is directly exchanged with steam generated by a steam boiler (for example, the steam boiler device 30) to raise the temperature to a target hot water outlet temperature set higher than the target hot water supply temperature. 2 heating steps, and when executing the first heating step and the second heating step, the output sharing between the water heater and the steam boiler is adjusted according to the set target hot water temperature. Related to hot water production method.

According to the present invention, it is possible to provide a hot water production system that is highly effective in reducing CO ₂ emissions and can also reduce running costs even when the tapped water temperature is increased.

1 is a schematic diagram showing a hot water production system according to a first embodiment of the present invention. It is a figure showing the heat pump circuit of the water heater of the above-mentioned embodiment. FIG. 2 is a functional block diagram showing the configuration of a control section of the embodiment. It is a schematic diagram for explaining the contents of the first hot water storage control of the above embodiment. It is a schematic diagram for explaining the content of the 2nd hot water storage control of the above-mentioned embodiment. FIG. 2 is a schematic diagram showing a first comparative example in which a hot water production system is constructed using only steam from a steam boiler device as a heating means. FIG. 3 is a schematic diagram showing a second comparative example in which a hot water production system is constructed using only a heat pump hot water supply system as a heating means. It is a typical diagram showing the hot water production system of the above-mentioned embodiment. It is a graph showing the effect of the above embodiment. It is a schematic diagram showing a hot water production system of a 2nd embodiment of the present invention. It is a schematic diagram showing the main part of the hot water production system of a 3rd embodiment of the present invention. It is a figure for explaining the content of the 1st hot water storage temperature control of the said embodiment.

<First embodiment>
Hereinafter, a hot water production system 1 according to a first embodiment of the present invention will be described with reference to the drawings. Note that the term "line" in this specification is a general term for lines through which fluid can flow, such as flow paths, routes, and pipes.

FIG. 1 is a schematic diagram showing a hot water production system 1 of this embodiment.
The hot water production system 1 of the present embodiment includes a first heating means 2 that heats water W1 to a first temperature while circulating it to a condenser of a heat pump type water heater; A second heating means 3 is provided which heats the water W1 to a second temperature higher than the first temperature by directly exchanging heat with the steam S generated by the steam boiler.

The first heating means 2 is constituted by a heat pump water heater system 10, which includes a plurality of heat pump water heaters, in this embodiment, a first heat pump water heater 11, a second heat pump water heater 12, and a third heat pump water heater 12. It includes a heat pump type water heater 13 (hereinafter also referred to as a first water heater 11, a second water heater 12, and a third water heater 13) and a first hot water tank 40 for storing hot water, which will be described later. The heat pump type water heaters 11, 12, and 13 (hereinafter also referred to as water heaters 11, 12, and 13) each preferably have an electrically driven refrigerant compressor, and the water W1 in the first hot water tank 40 is converted into a heat pump type water heater. The water is circulated through the condenser of the hot water supply system 10 and heated to a first temperature, for example, 50 to 70°C. The heat pump type hot water supply system 10 and the first hot water tank 40 are connected so as to be able to circulate through a first hot water supply line L1 and a first hot water supply return line L1R, which constitute a first circulation line.

Here, the plurality of water heaters 11, 12, and 13 all have the same configuration, and each water heater has a heat pump circuit 90. Therefore, as a representative of these circuits, the heat pump circuit 90 of the first water heater 11 will be explained.
As shown in FIG. 2, the heat pump circuit 90 of the first water heater 11 includes a refrigerant compressor 91, a condenser 92, an expansion valve 93, and an evaporator 94. These refrigerant compressor 91, condenser 92, expansion valve 93, and evaporator 94 are sequentially connected in an annular manner by a refrigerant circulation line L7, thereby forming a heat pump circuit 90.

The electrically driven refrigerant compressor 91 has a motor 95 as a driving source, and compresses a gaseous refrigerant R such as fluorocarbon gas into a high-temperature, high-pressure refrigerant. The condenser 92 condenses and liquefies the refrigerant R from the refrigerant compressor 91. The expansion valve 93 allows the refrigerant R sent from the condenser 92 to pass therethrough, thereby reducing the pressure and temperature of the refrigerant R. The evaporator 94 evaporates the refrigerant R sent from the expansion valve 93 using the heat source water W8 sent through the heat source water supply line L8 as a heat source. Note that in FIG. 1, the heat source water supply line L8 is not shown.

The heat source of the heat pump circuit 90 is not limited to heat source water such as waste hot water, but also exhaust gas (combustion gas, exhaust steam, etc.) from factory equipment, cooling air containing waste heat, outside air not containing waste heat, etc. It is possible to use various heat source gases.
Note that when the evaporator has a structure in which the heat transfer surface is exposed to the outside, the heat source gas is supplied to the heat transfer surface by a fan (for example, by ventilating the atmosphere). Furthermore, when the evaporator has a structure in which the heat transfer surface exists within a closed space (for example, a shell), the heat source gas is supplied to the heat transfer surface by a blower.

In this way, in the heat pump circuit 90 of the first water heater 11, the refrigerant R takes heat from the outside and vaporizes in the evaporator 94, while the refrigerant R radiates heat to the outside and condenses in the condenser 92. . Using such a principle, the heat pump circuit 90 of the first water heater 11 pumps heat from the heat source water W8 in the evaporator 94, and heats the water W1 from the first hot water tank 40 in the condenser 92. do. Then, the water W1 that has been heated and turned into hot water by passing through the condenser 92 is again supplied to the first hot water tank 40 through the first hot water supply line L1. In this way, the water W1 circulates between the first hot water tank 40 and the condenser 92 of the heat pump circuit 90.

The heat pump circuit 90 of the first water heater 11 is designed to maintain a constant degree of superheating of the refrigerant R (refrigerant temperature at the inlet of the refrigerant compressor 91), or to maintain a constant degree of supercooling of the refrigerant R (the refrigerant temperature at the inlet of the expansion valve 93). The opening degree of the expansion valve 93 is adjusted so that the temperature remains constant.

Furthermore, the output of the heat pump circuit 90 of the first water heater 11 may be changeable. For example, the configuration may be such that the rotation speed of the motor 95 of the refrigerant compressor 91 can be changed by inverter control.

Each of the water heaters 11, 12, and 13 is provided with a circulation pump (not shown) for circulating the water W1. Note that the circulation pump only needs to be provided substantially in each water heater 11, 12, 13, and may be provided in the water line in each water heater 11, 12, 13, or in each water heater 11, 12. , 13 may be provided in the first hot water supply line L1 or the first hot water supply return line L1R.
The circulation pump is driven with its rotational speed adjusted by, for example, inverter control, thereby adjusting the circulation flow rate. Note that a configuration may be adopted in which a flow rate adjustment valve is provided corresponding to each of the water heaters 11, 12, and 13, and the circulating flow rate is adjusted by controlling the opening degree of the flow rate adjustment valve. When a flow rate adjustment valve is provided, the circulation pump is driven at a predetermined rotational speed (constant drive frequency).

As shown in FIG. 1, each water heater 11, 12, 13 is provided with a hot water temperature sensor 14, 15, 16 that detects the temperature of hot water supplied from each water heater 11, 12, 13. Note that the hot water temperature sensors 14, 15, 16 only need to be substantially provided in the water heaters 11, 12, 13, and may be provided inside the water heaters 11, 12, 13, , 13, and may be provided in the first hot water supply line L1 before merging.

The service water W1 (hereinafter also referred to as hot water W1) heated by the plurality of water heaters 11, 12, and 13 (hereinafter also referred to as hot water W1) is supplied to the first hot water tank 40 after being joined by the first hot water supply line L1. Thereafter, the water W1 (hereinafter also referred to as hot water W1 or stored water W1) in the first hot water tank 40 branches off in the middle of the first hot water supply return line L1R, and then returns to each water heater 11, 12, 13. .
In this way, the water W1 circulates between the heat pump type hot water supply system 10 and the first hot water tank 40 through the first hot water supply line L1 and the first hot water supply return line L1R.
As a result, the heat pump type hot water system 10 circulates the water W1 in the first hot water tank 40 to the condenser 92 of the heat pump circuit 90 of each water heater 11, 12, 13 while maintaining the first temperature, for example, 50 to 70. Warm to ℃.

The first hot water tank 40 is a tank that stores hot water generated by circulating and heating the water W1 through the water heaters 11, 12, and 13.
The first hot water tank 40 is provided with a first temperature sensor 41 that detects the temperature of the stored hot water W1, and a first water level sensor 42 that detects the water level WL1 of the stored hot water W1. Then, based on the detection results of the first temperature sensor 41 and the first water level sensor 42, the first hot water storage control is performed. Details of this first hot water storage control will be explained later.

The hot water production system 1 of this embodiment includes a second hot water tank 240 in addition to the first hot water tank 40.
The first hot water tank 40 and the second hot water tank 240 are connected by a hot water delivery line L16. A hot water pump 243 for supplying hot water W1 in the first hot water tank 40 to the second hot water tank 240 is provided in the hot water delivery line L16.
The second hot water tank 240 is provided with a second temperature sensor 241 that detects the temperature of the stored hot water W2, and a second water level sensor 242 that detects the water level WL2 of the stored hot water W2. Then, based on the detection result of the second temperature sensor 241, steam supply control is performed. Further, based on the detection result of the second water level sensor 242, second hot water storage control is performed. In the second hot water storage control, the hot water W1 in the first hot water tank 40 is supplied to the second hot water tank 240 based on the detection result of the second water level sensor 242. Details of these steam supply control and second hot water storage control will be explained later.

Next, the second heating means 3 will be explained. The second heating means 3 includes a steam boiler device 30, the above-mentioned second hot water tank 240, and a heating steam supply line L2 that supplies the steam S generated in the steam boiler device 30 to the second hot water tank 240. , is provided.
The steam boiler device 30 is preferably a steam boiler having a gas-fired or oil-fired burner, and is composed of a plurality of once-through boilers 31 that generate steam S, for example.
The second heating means 3 heats the water heated by the first heating means 2 to a second temperature higher than the first temperature using steam S generated by the steam boiler device 30.

The heating steam supply line L2 includes a steam header 51 where steam S generated in the plurality of once-through boilers 31 gathers, a connection line 52 that connects the plurality of once-through boilers 31 and the steam header 51, and a steam header 51 that collects the steam S generated in the plurality of once-through boilers 31. and a steam supply line 53 that supplies the steam S to the second hot water tank 240. The steam supply line 53 is provided with a steam supply valve 54 for increasing the temperature. Further, the steam header 51 is provided with a pressure gauge 55 for detecting header pressure.

Steam S from the steam boiler device 30 is supplied into the second hot water tank 240 via the steam supply line L2 for heating. As a result, the hot water W2 stored in the second hot water tank 240 (hereinafter also referred to as stored water W2) is heated to a second temperature higher than the first temperature, for example, 75 to 95°C. That is, by blowing the steam S into the second hot water tank 240, direct heat exchange is performed between the hot water W2 stored in the second hot water tank 240 and the steam S from the steam boiler device 30. As a result, the temperature of the hot water W2 stored in the second hot water tank 240 increases. At this time, the total heat of the steam S from the steam boiler device 30, that is, the sensible heat and the latent heat, is utilized by direct heat exchange, and the temperature of the hot water W2 stored in the second hot water tank 240 is rapidly raised.

The hot water production system 1 of this embodiment includes a water supply tank 60 that stores water for use.
The water stored in the water supply tank 60 is supplied to the steam boiler device 30 as boiler water supply via the boiler water supply line L4. A boiler water supply pump 32 is provided in the boiler water supply line L4. The boiler water supply pump 32 is driven by, for example, inverter control so that the amount of water supplied to the steam boiler device 30 is adjusted. Note that the boiler feed pump 32 may be provided for each of the plurality of once-through boilers 31, or may be provided within the steam boiler device 30. Further, the amount of water supplied may be adjusted using a flow rate regulating valve.

Furthermore, the hot water production system 1 of this embodiment includes a make-up water line L5 for supplying the water stored in the water supply tank 60 to the first hot water tank 40. The makeup water line L5 is provided with a makeup water pump 61 and a makeup water valve 62. When the make-up water valve 62 is opened, the water stored in the water supply tank 60 is supplied to the first hot water tank 40 as make-up water. At this time, makeup water W5 (hereinafter also referred to as service water W5 or cold water W5) in the form of cold water is supplied into the first hot water tank 40 through the makeup water line L5. The water W1 in the first hot water tank 40 that has been replenished with the makeup water W5 is circulated and heated by the heat pump hot water supply system 10.

The hot water production system 1 of this embodiment includes a control unit 100 for performing various controls. FIG. 3 is a functional block diagram showing the configuration of the control unit 100. As shown in FIG. 3, the control unit 100 includes a hot water supply control unit 110, a boiler control unit 120, a steam supply control unit 130, a first hot water storage control unit 140, and a second hot water storage control unit 150.

Note that although the control unit 100 is composed of a plurality of functional blocks as described above, each block does not necessarily have to be physically separated, and the functions of the plurality of blocks can be realized by one CPU. may be configured. Furthermore, the control unit 100 may be divided into two or more parts, taking into account the arrangement and wiring of the devices to be controlled. For example, from the viewpoint of independent control of water heaters and boilers, the function of the hot water supply control unit 110 is preferably incorporated into the local control unit of each water heater, and the function of the boiler control unit 120 is designed to control a group of boilers. It is preferable to incorporate it into the number control panel.

The hot water supply control unit 110 controls the heat pump type hot water supply system 10. More specifically, it controls operations such as running and stopping the water heaters 11, 12, and 13, respectively. Further, the hot water supply control unit 110 controls the circulation pump corresponding to each water heater based on the detected temperature detected by the hot water temperature sensors 14, 15, and 16, and controls the hot water W1 from the water heaters 11, 12, and 13. Adjust the amount of hot water. It is preferable to use feedback control using a PID algorithm to adjust the amount of hot water supplied.
For example, focusing on the first water heater 11, the hot water supply control unit 110 controls the rotation speed of the circulation pump so that the detected temperature detected by the hot water temperature sensor 14 becomes a predetermined target hot water temperature. Adjust the amount of hot water. The same applies to the control of the second water heater 12 and the third water heater 13.
Note that the amount of hot water supplied may be adjusted by providing a flow rate adjustment valve corresponding to each of the water heaters 11, 12, and 13 and controlling the opening degree of the flow rate adjustment valve.
Thereby, the hot water W1 supplied from the water heaters 11, 12, and 13 is heated to the first temperature corresponding to the target hot water supply temperature so that the hot water W1 is always at the target hot water supply temperature.
Note that when the amount of heat source input to the heat pump circuit is small, the hot water supply temperature is controlled to be maintained at the target hot water supply temperature by reducing the amount of hot water supplied.

Note that as a method of controlling the hot water supply temperature of the water heaters 11, 12, and 13, the rotation speed of the motor 95 of the refrigerant compressor 91 is controlled so that the detected temperature of the hot water supply temperature sensors 14, 15, and 16 becomes the target hot water supply temperature. You may also adopt the method of As a result, the output of the refrigerant compressor 91 is gradually reduced as the hot water temperature in the first hot water tank 40 increases, making it possible to realize energy-saving operation of the water heater.

Here, the target hot water supply temperature is set to, for example, 50 to 85°C. More preferably, the temperature is 50 to 70°C. This preferable target hot water supply temperature will be described later using FIGS. 7 to 10.

The boiler control unit 120 performs control to increase or decrease the number of steam boiler devices 30 based on the header pressure value detected by the pressure gauge 55 provided in the steam header 51. More specifically, the amount of deviation between the header pressure value and the target steam pressure value is calculated so that the header pressure value becomes the target steam pressure value, and the number of boilers to be controlled to increase or decrease is calculated. This number increase/decrease control is well known, for example, as disclosed in Japanese Patent Application Laid-Open No. 2015-140975, so the explanation will be omitted here.

Next, steam supply control by the steam supply control section 130 will be explained.
The steam supply control unit 130 controls the opening degree of the temperature increase steam supply valve 54 based on the detected temperature detected by the second temperature sensor 241 of the second hot water tank 240. More specifically, the steam supply control unit 130 controls the opening degree of the temperature increase steam supply valve 54 so that the detected temperature detected by the second temperature sensor 241 becomes a predetermined target hot water storage temperature. to adjust the amount of steam S supplied. It is preferable to use feedback control to adjust the supply amount. For example, the operation amount for the temperature increase steam supply valve 54 is calculated by the PID algorithm so that the detected temperature of the second temperature sensor 241 converges to the target hot water storage temperature, and the steam supply control unit 130 An opening designation signal is output to the actuator circuit.
By performing such steam supply control, the temperature of the hot water W2 in the second hot water tank 240 is heated to a second temperature corresponding to the target hot water storage temperature so that the temperature always becomes the target hot water storage temperature.

Here, the target hot water storage temperature is higher than the target hot water supply temperature (first temperature), and is preferably set to 75 to 95°C. This preferable target hot water storage temperature will be described later using FIGS. 6 to 9.

Next, the first hot water storage control by the first hot water storage control section 140 will be explained with reference to FIG. 4.
The first hot water storage control unit 140 controls the make-up water valve 62 based on the detection result of the first water level sensor 42 .
As shown in FIG. 4, the first water level sensor 42 is constituted by an electrode type water level detector including a plurality of electrode rods, including a first electrode rod 421, a second electrode rod 422, and a third electrode rod. 423, a fourth electrode rod 424, and a fifth electrode rod 425. Further, although not shown, an electrode rod constituting a common electrode and an electrode rod for detecting an abnormal water level may be further provided.
Each of the electrode rods 421 to 425 detects whether the water level WL1 of the stored water W1 in the first hot water tank 40 has reached the lower end of each electrode rod, depending on whether or not the lower end thereof is immersed in water.

Here, the water level detected by the first electrode 421 is the water level LL, the water level detected by the second electrode 422 is the water level L, the water level detected by the third electrode 423 is the water level M, and the fourth electrode 424 is detected. Let the water level be a water level H, and the water level detected by the fifth electrode rod 425 be a water level HH. As shown in FIG. 4, each of the electrode rods is arranged in order from the lower end height position to the first electrode rod 421, the second electrode rod 422, the third electrode rod 423, and the fourth electrode rod 424. , the fifth electrode rod 425 is inserted into the first hot water tank 40.

In this embodiment, the first hot water storage control unit 140 controls the make-up water valve 62 based on the detection result of the first water level sensor 42 . For example, the first hot water storage control unit 140 opens the make-up water valve 62 when the first water level sensor 42 detects that the water level has fallen below the water level LL.

Here, a case in which the water level WL1 in the first hot water tank 40 changes from, for example, within the range of water level LL to water level L shown in FIG. 4 will be specifically described.
The stored water W1 stored in the first hot water tank 40 is supplied to the second hot water tank 240 through the hot water delivery line L16. As a result, the water level WL1 in the first hot water tank 40 decreases (see arrow A in FIG. 4).
Then, at a certain timing, when the lower end of the first electrode rod 421 is exposed from the water surface, the first water level sensor 42 detects that the water level WL1 has fallen below the water level LL.

When the first hot water storage control unit 140 detects that the water level WL1 has fallen below the water level LL, it determines that the first hot water tank 40 is in a state immediately before a drought, opens the make-up water valve 62, and stores water in the water supply tank 60. The first hot water tank 40 is replenished with make-up water W5, which is unheated water.

By performing such control, the water level WL1 recovers (see arrow B in FIG. 4).
Then, when the water surface contacts the fifth electrode rod 425 and the tip of the fifth electrode rod 425 dips into the water surface, the first water level sensor 42 detects that the water level WL1 has exceeded the water level HH.
The first hot water storage control unit 140 closes the make-up water valve 62 when detecting that the water level WL1 has exceeded the water level HH.

With such control, when the hot water W1 in the first hot water tank 40 becomes low, makeup water W5 can be replenished from the makeup water line L5 at an appropriate timing.

Note that in this embodiment, when the water level WL1 in the first hot water tank 40 falls below the water level LL, the makeup water valve 62 is opened to supply makeup water W5 into the first hot water tank 40. , the makeup water W5 may be supplied using another water level as the water level threshold. For example, when the water level WL1 in the first hot water tank 40 falls below the water level L, the supplementary water W5 may be supplied into the first hot water tank 40. In this case, control is performed using the detection results of the second electrode rod 422.
Note that in this embodiment, when the water level WL1 in the first hot water tank 40 exceeds the water level HH, the make-up water valve 62 is closed to stop the supply of make-up water W5; The supply of makeup water W5 may be stopped as the threshold value. For example, when the water level WL1 in the first hot water tank 40 exceeds the water level M, the supply of makeup water W5 may be stopped. In this case, control is performed using the detection results of the third electrode rod 423.
In this way, the water level threshold for performing the first hot water storage control can be selected from among a plurality of water levels. This allows you to determine the minimum amount of hot water W1 that you want to store in the first hot water tank 40, the amount of make-up water W5 that you want to replenish at once, the heating time that is required depending on the water heater capacity and the amount of replenishment, etc. Taking this into account, the water level threshold for starting and stopping the supply of makeup water W5 can be selected.

Then, the first hot water storage control unit 140 further executes a number control of switching the number of water heaters 11 , 12 , and 13 in operation based on the detection result of the first temperature sensor 41 .
Specifically, as shown in FIG. 4, when the water temperature in the first hot water tank 40 rises, the number of water heaters in operation is reduced by one each time the temperature detected by the first temperature sensor 41 exceeds the temperature threshold by one step. Execute control to reduce the number of units.
In the following, the first target hot water storage temperature, which is the target hot water storage temperature in the first hot water tank 40, is set to 70°C, and the temperature threshold for executing the number control is set to at least 50°C or 60°C. An example will be explained.

When the temperature rises, if the temperature detected by the first temperature sensor 41 is 50° C. or lower, all three water heaters 11, 12, and 13 continue to operate.
Next, when the temperature rises and the temperature detected by the first temperature sensor 41 exceeds 50° C., the operation of one of the three water heaters is stopped, and only two water heaters continue to operate. For example, among the water heaters 11, 12, and 13, the operation of the third water heater 13 is stopped, and only the first and second water heaters 11, 12 continue to operate.
Next, when the temperature further rises and the temperature detected by the first temperature sensor 41 exceeds 60° C., the operation of two of the three water heaters is stopped, and only one water heater continues to operate. For example, among the water heaters 11, 12, and 13, the operation of the second and third water heaters 12 and 13 is stopped, and only the first water heater 11 continues to operate.

Then, even when the temperature further rises and the temperature detected by the first temperature sensor 41 reaches 70° C., which is the first target hot water storage temperature, the system continues to maintain the temperature near the first target hot water storage temperature. Only one water heater will continue to operate.
Note that when the temperature reaches the vicinity of the first target hot water storage temperature, the hot water supply control unit 110 may continue to perform constant hot water supply temperature control, or may perform feedback control based on the first temperature sensor 41. That is, based on the first target hot water storage temperature and the temperature detected by the first temperature sensor 41 provided in the first hot water tank 40, feedback control of the hot water supply temperature is performed to maintain the temperature near the first target hot water storage temperature. You may do so. In this case, the hot water supply temperature of the water heater is adjusted according to the temperature fluctuation of the hot water W1 occurring in the first hot water tank 40. Note that the hot water temperature of the water heater may be adjusted by controlling the rotation speed of the motor 95 of the refrigerant compressor 91, or by controlling the rotation speed of the circulation pump of the water heater.

Then, when the temperature further increases and the temperature detected by the first temperature sensor 41 exceeds 75° C., the operation of the first water heater 11 is also stopped. That is, the operation of all water heaters 11, 12, and 13 is stopped.

Next, a description will be given of the time when the temperature decreases.
When the temperature in the first hot water tank 40 decreases, the number of water heaters in operation is increased by one each time the temperature detected by the first temperature sensor 41 falls one step below the temperature threshold.
For example, if the temperature detected by the first temperature sensor 41 exceeds 75°C and then falls below 70°C, only one water heater starts operating. Next, when the temperature drops below 60°C, the two water heaters are put into operation. Next, when the temperature drops below 50°C, all three water heaters are put into operation.

In this way, since control is performed to increase or decrease the number of water heaters in operation according to the temperature of the water W1 in the first hot water tank 40, the water temperature in the first hot water tank 40 can be appropriately managed. Furthermore, power consumption can be reduced.

Note that a state confirmation time may be provided when switching the number of water heaters in operation according to the temperature detected by the first temperature sensor 41. That is, when it is determined that the temperature detected by the first temperature sensor 41 has continued to exceed a predetermined temperature threshold for a first predetermined period of time during a temperature rise, control such as switching the number of water heaters in operation is performed. It may also be configured to execute. Further, when the temperature falls, if it is determined that the state in which the temperature detected by the first temperature sensor 41 remains below a predetermined temperature threshold continues for a second predetermined period of time, control such as switching the number of water heaters in operation is performed. It may also be configured to execute.
With such control, it is possible to perform control such as changing the number of water heaters in operation based on the confirmation time that the detected temperature continues to decrease or the detected temperature continues to increase. Therefore, when the temperature detected by the first temperature sensor 41 fluctuates around the temperature threshold, it is possible to prevent a situation where the water heater is frequently started and stopped. This reduces the risk of failure of water heaters and hot water supply control equipment (water pumps, water valves, etc.).
Preferably, the set value of the status confirmation time is adjustable. The set value of the status confirmation time can be adjusted manually or automatically, and can be set to a value larger than 0. Note that the state confirmation time is measured using an internal timer or the like of the control unit 100.

Note that the first hot water storage control unit 140 may shift the number of water heaters in operation in a predetermined temperature range by one step between when the temperature rises and when the temperature falls, rather than making the number of water heaters in operation approximately the same as shown in FIG. 4. good.
For example, a case will be described in which the first target hot water storage temperature in the first hot water tank 40 is set to 70°C to 75°C.
At this time, when the temperature rises, if the temperature detected by the first temperature sensor 41 is 60° C. or lower, all three water heaters continue to operate. If the temperature exceeds 60℃, only two water heaters will continue to operate. If the temperature exceeds 70℃, only one water heater will continue to operate. If the temperature exceeds 75℃, all three water heaters will stop operating.
On the other hand, when the temperature falls, if the temperature detected by the first temperature sensor 41 falls below 70°C, only one water heater starts operating. When the temperature drops below 60°C, the two water heaters are put into operation. When the temperature drops below 50℃, all three water heaters are put into operation.
Even with such control, when the temperature detected by the first temperature sensor 41 fluctuates around the temperature threshold, it is possible to prevent a situation where the water heater is frequently started and stopped.

Note that in this embodiment, the temperature of the hot water supplied from the water heaters 11, 12, and 13 is basically constant, except when performing feedback control based on the temperature detected by the first temperature sensor 41 described above. controlled. For example, if the first target hot water storage temperature in the first hot water tank 40 is 70°C, the target hot water supply temperature is set to 70°C or a temperature slightly higher than 70°C, for example 72°C. If the first target hot water storage temperature in the first hot water tank 40 is 75°C, the target hot water supply temperature is set to 75°C or a temperature slightly higher than 75°C, for example 77°C. The water heaters 11, 12, and 13 supply hot water W1 at a first temperature corresponding to this target hot water supply temperature.

Note that when the hot water supply control unit 110 is incorporated into the local control unit of each water heater, the first hot water storage control unit 140 outputs a control command to the local control unit of each water heater, and upon receiving this control command, the first hot water storage control unit 140 outputs a control command to the local control unit of each water heater. The water heater will now work.

Note that stopping the operation of the water heaters described above includes stopping the operation of the circulation pump of each water heater 11, 12, and 13, and closing the flow rate adjustment valve corresponding to each water heater 11, 12, and 13. , also includes the operation of stopping hot water supply from the water heater. It also includes stopping the driving of the refrigerant compressor 91 and stopping the refrigerant circulation in the heat pump circuit.

In addition, a configuration is adopted in which the water heaters among the water heaters 11, 12, and 13 are appropriately determined based on the status and operation history of each water heater as to which water heater should be prioritized for stopping/resuming operation. You can. Alternatively, it may be determined in advance.

Next, the second hot water storage control by the second hot water storage control section 150 will be described with reference to FIG. 5.
The stored water W2 stored in the second hot water tank 240 is supplied as hot water W6 to a hot water demand location (not shown) through the hot water outlet line L6. As a result, the water level WL2 in the second hot water tank 240 decreases.
In such a situation, the second hot water storage control unit 150 controls the hot water pump 243 based on the detection result of the second water level sensor 242.
In this embodiment, the second water level sensor 242 detects three levels: water level L, water level M, and water level H, and the number of detected water levels is different from that of the first water level sensor 42, but other than that, the structure is the same. Since it is the same as the first water level sensor 42, the explanation will be omitted here.

When the second hot water storage control unit 150 detects that the water level WL2 of the stored water W2 in the second hot water tank 240 has fallen below the water level L when the water level is falling (see arrow A in FIG. 5), the second hot water storage control unit 150 It is determined that the stored water W2 in the tank 240 is in a shortage state, and the hot water pump 243 is driven. Thereby, the stored water W1 in the first hot water tank 40 is supplied into the second hot water tank 240.
At this time, the hot water W1 in the first hot water tank 40 (the hot water W1 that has been heated to the first temperature by the water heater) is supplied to the second hot water tank 240, so that the water is stored in the second hot water tank 240. Considering that the temperature of the water W2 (the stored water W2 that has been heated to a second temperature higher than the first temperature using the steam S) will decrease, the heating steam supply valve 54 is fully opened, As much steam S as possible is supplied to the second hot water tank 240. Note that, at this time, the steam supply control unit 130 controls the temperature increase steam supply valve 54 to be fully opened, regardless of the temperature detected by the second temperature sensor 241, and controls the temperature increase steam supply valve 54 to be fully opened. The temperature of the stored water W2 in 240 is raised as early as possible.

By performing such control, the water level WL2 recovers (see arrow B in FIG. 5). Then, at a certain timing when the water level is rising, the second water level sensor 242 detects that the water level WL2 has exceeded the water level M.
When the second hot water storage control unit 150 detects that the water level WL2 in the second hot water tank 240 has exceeded the water level M, the second hot water storage control unit 150 controls the heating steam supply valve 54 to a normal temperature based on the temperature detected by the second temperature sensor 241. Return to temperature control. Note that at this point, the water level WL2 in the second hot water tank 240 is still not high, so the hot water pump 243 continues to operate.

Next, when the water level WL2 further rises and it is detected that the water level WL2 in the second hot water tank 240 exceeds the water level H, it is determined that the stored water W2 in the second hot water tank 240 has reached a sufficient amount. , the drive of the hot water pump 243 is stopped. In addition, the control of the steam supply valve 54 for temperature increase maintains the normal temperature control state by the steam supply control part 130.
After that, when the water level WL2 of the stored water W2 in the second hot water tank 240 decreases due to hot water consumption by the hot water demand point and falls below the water level L again, the hot water pump 243 is driven as described above. Hot water W1 in the hot water tank 40 is supplied into the second hot water tank 240.

With the second hot water storage control as described above, when the hot water W2 in the second hot water tank 240 becomes low, hot water can be supplied from the first hot water tank 40 to the second hot water tank 240 at an appropriate timing. Furthermore, the temperature of the hot water in the second hot water tank 240 can be appropriately controlled.

Regarding the control of the heating steam supply valve 54, it is also possible to adopt a configuration in which normal temperature control is always performed based on the temperature detected by the second temperature sensor 241, regardless of the water level WL2 in the second hot water tank 240. good.
Note that when it is detected that the water level WL2 in the second hot water tank 240 has exceeded the water level H, the temperature raising steam supply valve 54 may be closed.
Note that the second hot water storage control section 150 may control the temperature raising steam supply valve 54 via the steam supply control section 130.

Note that the first water level sensor 42 and the second water level sensor 242 are not limited to electrode type water level detectors, and various types of water level detectors may be used. For example, a plurality of float-type water level detectors may be provided so that each water level threshold can be detected. Further, an electrode type water level detector and a float type water level detector may be used in combination. Furthermore, a plurality of water level thresholds may be detected using a water level detection unit such as a pressure type water level sensor or a capacitance type water level sensor that can continuously measure the water level.

As shown in this embodiment, by adopting a configuration in which hot water is circulated between the water heater and the first hot water tank 40 and steam is supplied into the second hot water tank 240, the inside of the first hot water tank 40 is It becomes possible to maintain the temperature near the first temperature in the second hot water tank 240 and raise the temperature to the second temperature in the second hot water tank 240. Therefore, hot water at the second temperature can be stably produced.

As described above, the hot water production system 1 of the present embodiment includes the first heating means 2 that heats the water W1 to the first temperature while flowing it to the condenser of the heat pump hot water supply system 10, and the first heating A second heating means 3 is provided for heating the water W1 heated by the means 2 to a second temperature higher than the first temperature using steam S generated by a steam boiler device 30.
The effects of adopting this configuration will be explained in detail using FIGS. 6 to 8.

FIG. 6 shows a first comparative example in which a hot water production system was constructed using only steam S from the steam boiler device 30 as a heating means.
The temperature of hot water required by the hot water demand site varies depending on its purpose, but for example, when cleaning food and medicine bottles, pasteurizing sterilization (sterilizing bottling), etc. Hot water may be required. Therefore, a case will be described in which the hot water production system supplies hot water in a high temperature range, for example, 90° C., to a hot water demand location.

The hot water production system 5 in FIG. 6 uses only the steam S from the steam boiler device 30 as a heating means. Here, the steam boiler has a gas-fired or oil-fired burner and generates steam using fossil fuel. Therefore, the CO ₂ emissions and running costs of this hot water production system 5 are relatively high, and significant reductions are required.

Therefore, it is conceivable to adopt a hot water production system using a heat pump hot water supply system 10 with a high COP as a heating means.
FIG. 7 shows a second comparative example in which a hot water production system 6 is constructed using only the heat pump hot water supply system 10 as a heating means. The CO ₂ emission coefficient of electricity (0.51 kg CO ₂ /kWh) is _larger than that of city gas 13A (0.18 kg CO ₂ /kWh), but when compared in terms of CO ₂ emissions per output, COP's A high heat pump will require less than a steam boiler. In addition, the unit price of electricity (about 15 yen/kWh) is higher than the unit price of city gas 13A fuel (about 6.2 yen/kWh), but when comparing the running cost per output, heat pumps with higher COP are better than heat pumps with higher COP. It will be cheaper than a boiler. Therefore, the hot water production system 6 has lower CO ₂ emissions and running costs than the hot water production system 5 in FIG. 6 .

However, with heat pumps, if the water supply temperature is low, the COP is relatively high and the effect of reducing _CO2 emissions is high, but when the hot water supply temperature is raised and used, the COP is relatively low and the _CO2 emissions are The reduction effect will decrease.
For example, the COP of a heat pump when supplying hot water at 90° C. is equivalent to 2.8. Therefore, when compared with the hot water production system 5 that uses only steam from a steam boiler as a heating means, the reduction effect on CO ₂ emissions (CO ₂ emission reduction ratio) remains at about 10%. Furthermore, the running cost reduction effect (running cost reduction ratio) remains at about 20%.

Next, the hot water production system 1 of this embodiment, that is, the first heating means 2 that heats the water W1 to a first temperature while circulating it through the condenser of the heat pump hot water supply system 10; About a hybrid hot water production system comprising: second heating means 3 for heating water W1 heated by water W1 to a second temperature higher than the first temperature using steam S generated by a steam boiler device 30; think about.

FIG. 8 shows a schematic diagram showing an overview of such a hot water production system 1.
In such a hot water production system 1, the heat pump hot water supply system 10 as the first heating means 2 heats the water W1 to a temperature range where it can be operated with high efficiency, for example, to 70°C, and The heated water W1 can be heated to a high temperature range, for example, 90° C., using the steam S from the steam boiler device 30, and hot water in the high temperature range can be produced with high efficiency.

Here, the COP of the heat pump when the hot water supply temperature is 70° C. is, for example, equivalent to 4.2, which is very high. In the hot water production system 1 of this embodiment, the heat pump is responsible for heating up to a temperature range that can maintain such a high COP.
For example, when the hot water production system 1 wants to produce hot water at 90°C, the heat pump is responsible for heating up to 70°C. At this time, the heat pump will be in charge of approximately 60% to 80% (load factor 60% to 80%) of the total heat output required to produce hot water at 90°C.
The steam boiler is responsible for raising the temperature from 70°C to 90°C. At this time, the steam boiler will be in charge of about 20% to 40% (load factor 20% to 40%) of the total heat output necessary to produce hot water at 90°C.

The hot water production system 1 using such a combination of a heat pump and a steam boiler reduces CO ₂ emissions compared to the hot water production system 5 that uses only steam from the steam boiler as a heating means. The reduction effect is approximately 30%, which is extremely high. Furthermore, the running cost reduction effect is approximately 35%, which is a very high reduction effect.

In this way, by using the hot water production system 1 of this embodiment, even when the tapping temperature is increased, CO ₂ emissions and running costs can be extremely effectively reduced.
In addition, in the hot water production system 1 of this embodiment, the output ratio of the heat pump and the steam boiler, that is, the share of heat output (output share) of each, can be adjusted appropriately according to the target hot water temperature. , it is possible to extremely effectively reduce CO ₂ emissions and running costs.
It is preferable that the relationship between the output ratios of the heat pump and the steam boiler according to the target hot water outlet temperature of the hot water production system 1 is stored in a table or a calculation formula. For example, the configuration is such that a target hot water outlet temperature can be set, and an appropriate output ratio of the heat pump and steam boiler is set according to the set target hot water outlet temperature.

FIG. 9 is a graph showing the CO ₂ emission reduction ratio and the running cost reduction ratio in the case of producing and dispensing hot water at, for example, 90° C. using the hot water production system 1 of this embodiment.

The horizontal axis of the graph in FIG. 9 is the hot water temperature of the heat pump. The vertical axis of the line graph in FIG. 9 is the CO ₂ emission reduction ratio and the running cost reduction ratio.
Here, the CO ₂ emission reduction ratio is the reduction in the hot water production system 1 of this embodiment, assuming that the CO ₂ emissions of the hot water production system 5 that uses only steam from the steam boiler as a heating means is 100%. It shows the percentage of CO ₂ emissions produced. In other words, if the CO ₂ emission reduction ratio is 25%, this means that by switching to the hot water production system 1, CO ₂ emissions from 100% can be reduced to 75%.
On the other hand, the running cost reduction ratio is the running cost reduced by the hot water production system 1 of this embodiment, when the running cost of the hot water production system 5 that uses only steam from the steam boiler as a heating means is 100%. It shows the percentage of That is, if the running cost reduction ratio is 30%, it means that by switching to the hot water production system 1, the running cost can be reduced from 100% to 70%.
The vertical axis of the bar graph in FIG. 9 indicates the output ratio of the heat pump and the steam boiler, that is, the share of heat output (output share) of each.
The COP at the hot water supply temperature of the heat pump is attached to the bar graph showing the output ratio of the heat pump. The higher the hot water temperature, the lower the COP.

In the line graph of Figure 9, when comparing the data for heat pump hot water supply temperature = 90°C and the data for heat pump hot water supply temperature = 50°C to 80°C, it is found that when hot water of 90°C is produced using only a heat pump (heat pump hot water supply temperature = Compared to 90°C data), heating the plant to 50 to 80°C using a heat pump and then raising the temperature to 90°C using steam is clearly more effective in reducing _CO2 emissions and in reducing running costs. I can understand that it is expensive. For example, heating to 50 to 70°C using a heat pump and then raising the temperature to 90°C using steam will have a high _CO2 reduction effect and running cost reduction effect.
Furthermore, from the trend of the line graph, it should be understood that the effects of the present invention can be obtained even if the temperature is heated to 85°C using a heat pump and then heated to 90°C using steam. I can do it.

In this way, the hot water production system 1 of the present embodiment, that is, the first heating means 2 that heats the water W1 to the first temperature while circulating it to the condenser of the heat pump hot water supply system 10; A second heating means for raising the temperature of the water W1 heated by the means 2 to a second temperature higher than the first temperature by using the steam S generated by the steam boiler device 30. By using the system, CO ₂ emissions and running costs can be extremely effectively reduced even when the system increases the hot water temperature.

The first heating means 2 of the hot water production system 1 of this embodiment heats the water W1 to a first temperature while circulating it to the condenser of the heat pump water heater.
In this way, if the first heating means 2 is a circulation type, compared to a once-through type, the water flow rate to the condenser 92 of the heat pump circuit 90 can be reduced, and the water W1 can be efficiently used. This makes it possible to heat the vehicle, making it possible to build a system with excellent running cost performance.

The second heating means 3 of the hot water production system 1 of the present embodiment directly exchanges heat with the water W1 heated by the first heating means 2 with the steam S generated by the steam boiler device 30. The temperature has increased to a second temperature higher than the first temperature.
In this way, by directly exchanging heat between the water W1 heated by the first heating means 2 and the steam S generated by the steam boiler device 30, the water W1 heated by the first heating means 2 is heated. Raise the temperature quickly. That is, by utilizing the total heat (sensible heat and latent heat) of the steam S, the temperature of the water W1 heated by the first heating means 2 is rapidly raised. Therefore, the control responsiveness of the tapping temperature is also improved.

In order to obtain these effects, it is particularly recommended to use a heat pump type water heater with an electrically driven refrigerant compressor as the water heater, and use a steam boiler with a gas-fired or oil-fired burner as the steam boiler. preferable.
By setting the first temperature to 50 to 85°C and setting the second temperature to 75 to 95°C, which is higher than the first temperature, the effects of the present invention can be appropriately obtained. . Preferably, the first temperature is 50 to 80°C, and the second temperature is higher than the first temperature, and is 75 to 95°C. More preferably, the first temperature is 50 to 70°C, and the second temperature is 75 to 95°C.
In this way, by combining a heat pump water heater with an electrically driven refrigerant compressor and a steam boiler with a burner that burns fossil fuels, and by appropriately setting the heating temperature range of each, the heat pump water heater Compared to producing high-temperature water by itself or by using a steam boiler alone, it is possible to obtain a high CO ₂ emission reduction effect and a high running cost reduction effect.

The hot water production system 1 of the present embodiment preferably includes a second hot water tank 240 as the second heating means 3; A configuration may be adopted in which steam is directly supplied to the hot water W1 in the flow path thereof.

In addition, in order to perform appropriate hot water storage control, it is preferable to have a plurality of water heaters constituting the heat pump type hot water supply system 10, but it may be one. In the case of one water heater, the control using the plurality of water heaters described in the present embodiment is not performed, and hot water supply on/off control based on the water temperature of the first hot water tank 40 is performed.
In addition, when using a plurality of water heaters, the number can be any number greater than or equal to two.

Note that, although it is preferable to have a plurality of boilers constituting the steam boiler device 30, there may be one boiler. In the case of one steam pressure generator, the combustion rate may be controlled based on the measured steam pressure value and the target steam pressure value.
In addition, when using multiple boilers, it can be set as two or more arbitrary boilers.
Moreover, the boiler that constitutes the steam boiler device 30 may be a boiler other than a once-through boiler.

Note that the produced hot water can be used not only for washing food and medicine bottles and for sterilizing pasteurizers, but also for various other purposes.
For example, when hot water is used in the food and beverage field, it can be used for purposes such as heating raw materials and processed products, washing bottles, and cleaning-in-place (CIP) for manufacturing equipment.
In addition, when using steam in the food and beverage field, the steam S generated by the steam boiler device 30 can be used for high-temperature cooking (frying, steaming, and stir-frying), retort pot sterilization (pouch and canned food sterilization), and emplacement of manufacturing equipment. It can be used for sterilization (SIP), backup for hot water production, etc.
If hot water is used in the machinery field, it can be used for hot water washing, degreasing, etc.
In these applications, hot water in a high temperature range of about 75°C to 95°C may be required, and in cases where hot water in such a high temperature range is required, the hot water production system 1 of the present embodiment is particularly suitable. Available.

According to the hot water production system 1 of this embodiment described above, the following effects are achieved.

(1) The hot water production system 1 of the present embodiment includes a first heating process in which water W1 is heated to a first temperature while being circulated through the condensers 92 of the heat pump water heaters 11, 12, and 13 of the heat pump water supply system 10. means 2, and second heating in which the water heated by the first heating means 2 is heated to a second temperature higher than the first temperature by directly exchanging heat with the steam S generated by the steam boiler device 30. means 3.
In this way, when heating water, the first heating means 2 heats it up to a temperature that can be heated with high efficiency by the heat pump type water heaters 11, 12, and 13, and further temperature increases are performed using the steam S. Since this is performed by direct heat exchange, it is possible to provide a hot water production system that is highly effective in reducing CO ₂ emissions and running costs even when the tapping temperature is increased. Furthermore, since steam S is used to raise the temperature and direct heat exchange is performed, the temperature control responsiveness is extremely good. In addition, since the first heating means is a circulation type, it is possible to efficiently heat the water while reducing the flow rate of water to the condenser 92 compared to a once-through type. You can build a running system with excellent cost performance.

(2) The water heaters 11, 12, 13 of the hot water production system 1 of this embodiment have an electrically driven refrigerant compressor 91, and the steam boiler device 30 has a gas combustion or oil combustion burner. The first temperature is 50-70°C and the second temperature is 75-95°C.
In this way, by combining a heat pump water heater with an electrically driven refrigerant compressor and a steam boiler with a burner that burns fossil fuels, and by appropriately setting the heating temperature range of each, the heat pump water heater Compared to producing high-temperature water by itself or by using a steam boiler alone, it is possible to obtain a high CO ₂ emission reduction effect and a high running cost reduction effect.

(3) The first heating means 2 of the hot water production system 1 of the present embodiment is supplied with unheated water W5 and generated by circulating and heating this water W5 through the water heaters 11, 12, and 13. The second heating means 3 includes a first hot water tank 40 that stores hot water W1, and a second hot water tank 240 to which hot water is supplied from the first hot water tank 40, and a steam boiler device 30 in the second hot water tank 240. It includes a temperature-raising steam supply line L2 that supplies the generated steam S, and a temperature-raising steam supply valve 54 provided in the temperature-raising steam supply line L2.
In this way, by adopting a configuration in which the hot water W1 is circulated between the water heaters 11, 12, 13 and the first hot water tank 40 and the steam S is supplied into the second hot water tank 240, the first hot water tank It becomes possible to maintain the temperature in the vicinity of the first temperature in the hot water tank 40 and raise the temperature to the second temperature in the second hot water tank 240. Therefore, hot water at the second temperature can be stably produced.

(4) The second heating means 3 of this embodiment includes a second temperature sensor 241 that detects the temperature of the hot water W2 in the second hot water tank 240, and the detected temperature of the second temperature sensor 241 reaches the target hot water storage temperature. The opening degree of the steam supply valve 54 for temperature rise is controlled so that the temperature rises.
Thereby, the hot water temperature within the second hot water tank 240 can be appropriately controlled.

(5) The hot water production system 1 of the present embodiment includes a first water level sensor 42 that detects the water level WL1 in the first hot water tank 40, a makeup water line L5 that supplies water to the first hot water tank 40, and a makeup water line L5. A make-up water valve 62 provided in the line L5 is provided, and when the detected water level of the first water level sensor 42 falls below the set water level, the make-up water valve 62 is opened.
Thereby, when the hot water W1 in the first hot water tank 40 becomes low, it is possible to replenish the water W5 from the replenishment water line L5 at an appropriate timing.

(6) The hot water production system 1 of this embodiment uses the hot water pump 243 provided in the hot water delivery line L16 that connects the first hot water tank 40 and the second hot water tank 240, and the water level WL2 of the second hot water tank 240. A second water level sensor 242 is provided, and when the detected water level of the second water level sensor 242 falls below the set water level, the hot water pump 243 is driven.
Thereby, when the hot water W2 in the second hot water tank 240 becomes low, hot water can be supplied from the first hot water tank 40 to the second hot water tank 240 at an appropriate timing.

(7) The hot water production system 1 of the present embodiment includes a first temperature sensor 41 that detects the temperature of the hot water W1 in the first hot water tank 40, and the first heating means 2 includes a plurality of water heaters 11, 12. , 13, and the first hot water tank 40 is set with multiple temperature thresholds for changing the number of water heaters 11, 12, 13 in operation. Each time the temperature detected by the first temperature sensor 41 falls below the temperature threshold by one step, the number of water heaters 11, 12, and 13 in operation is increased by one, and when the temperature in the first hot water tank 40 increases, Each time the temperature detected by the first temperature sensor 41 exceeds the temperature threshold by one step, number control is performed in which the number of water heaters 11, 12, and 13 in operation is decreased by one.
In this way, since the number of water heaters 11, 12, and 13 in operation is increased or decreased according to the temperature of the hot water in the first hot water tank 40, the temperature of the hot water in the first hot water tank 40 can be appropriately managed. Furthermore, power consumption can be reduced.

(8) The water heaters 11, 12, and 13 of the hot water production system 1 of this embodiment include a refrigerant compressor 91 provided on the heat pump circuit 90, and a hot water temperature that detects the hot water temperature of the water heaters 11, 12, and 13. The refrigerant compressor 91 is provided with sensors 14, 15, and 16, and controls the rotation speed of the refrigerant compressor 91 so that the temperature detected by the hot water supply temperature sensors 14, 15, and 16 becomes the target hot water temperature.
Thereby, the hot water supply temperature of the water heaters 11, 12, and 13 can be appropriately controlled.

(9) The hot water production method of the present embodiment includes a first heating step in which water is heated to a first temperature while being circulated through the condensers 92 of the heat pump water heaters 11, 12, and 13; A second heating step is provided in which the heated water is directly exchanged with the steam S generated by the steam boiler device 30 to raise the temperature to a second temperature higher than the first temperature.
In this way, when heating water, the heat pump type water heaters 11, 12, and 13 heat the water to a temperature that can be heated with high efficiency in the first heating step, and further temperature increases are performed directly with the steam S. Since this is performed by heat exchange, it is possible to provide a hot water production method that is highly effective in reducing CO ₂ emissions and running costs even when the tapping temperature is increased. Furthermore, since steam S is used to raise the temperature and direct heat exchange is performed, the temperature control responsiveness is extremely good. In addition, since the first heating process is a circulation method, it is possible to efficiently heat the service water while reducing the flow rate of water to the condenser 92 compared to the once-through method, which improves running cost performance. A superior hot water production method can be constructed.

<Second embodiment>
Next, a second embodiment will be described with reference to FIG. 10. Note that descriptions of configurations similar to those in the first embodiment will be omitted.
The hot water production system 1 of the second embodiment further includes a preheating heat exchanger 75 that indirectly exchanges heat between makeup water W5 flowing through the makeup water line L5 and steam S from the steam boiler device 30.
FIG. 10 is a diagram showing a hot water production system 1 according to a second embodiment of the present invention.

As shown in FIG. 10, in this embodiment, a preheating heat exchanger 75 is provided in the makeup water line L5. The preheating heat exchanger 75 is an indirect heat exchanger, and performs indirect heat exchange between the water (cold water) W5 from the water supply tank 60 supplied through the make-up water line L5 and the steam from the steam boiler device 30. The preheating heat exchanger 75 is provided downstream of the make-up water valve 62.

The steam supply line 53 (heating steam supply line L2) of this embodiment branches in the middle, one end is connected to the second hot water tank 240, and the other end is connected to the preheating heat exchanger 75. The line connected to the second hot water tank 240 is provided with a heating steam supply valve 54 similar to the first embodiment. On the other hand, the line connected to the preheating heat exchanger 75 constitutes a preheating steam supply line L10, and a preheating steam supply valve 76 is provided in this preheating steam supply line L10.

These preheating heat exchanger 75, preheating steam supply line L10, and preheating steam supply valve 76 constitute additional heating means and have a function of heating makeup water W5 supplied through makeup water line L5. .

In this embodiment, the first hot water storage control unit 140 controls the preheating steam supply valve 76 in addition to the hot water storage control described in the first embodiment. Specifically, when the make-up water valve 62 is opened, the preheating steam supply valve 76 is also opened. Thereby, it is possible to prevent the water temperature of the stored water W1 in the first hot water tank 40 from rapidly decreasing due to the make-up water W5 supplied through the make-up water line L5.

Similar to the first embodiment, the make-up water valve 62 is opened when it is detected that the water level WL1 in the first hot water tank 40 has fallen below, for example, the water level LL. As a result, the makeup water W5, which is cold water stored in the water supply tank 60, is supplied to the first hot water tank 40, and the stored water W1 in the first hot water tank 40 can be replenished. Naturally, the temperature of the stored water W1 in the first hot water tank 40 decreases.

The preheating heat exchanger 75 in this embodiment is provided to prevent the temperature of the stored water W1 in the first hot water tank 40 from decreasing as much as possible due to such replenishment of the makeup water W5. That is, when the make-up water valve 62 is opened, the preheating steam supply valve 76 is also opened, thereby warming the make-up water W5 supplied into the first hot water tank 40 through the make-up water line L5. Thereby, when replenishing the make-up water W5 from the make-up water line L5 to the first hot water tank 40, the temperature of the make-up water W5 can be increased.
Therefore, when the water heater circulates and heats the water W1 in the first hot water tank 40, it can be heated to the first temperature relatively quickly.

According to the hot water production system 1 of this embodiment described above, in addition to (1) to (9), the following effects are achieved.

(10) The hot water production system 1 of the present embodiment includes a preheating heat exchanger 75 that indirectly exchanges heat between makeup water W5 flowing through the makeup water line L5 and steam, and a steam boiler device 30 in the preheating heat exchanger 75. A preheating steam supply line L10 that supplies the steam S generated in Open the steam supply valve 76.
Thereby, when replenishing water from the replenishment water line L5 to the first hot water tank 40, the temperature of the replenishment water can be increased.

<Third embodiment>
Next, a third embodiment will be described with reference to FIGS. 11 and 12. Note that descriptions of configurations similar to those in the first embodiment will be omitted.
The hot water production system 1 of the third embodiment includes a switching means 290 (switching valve 291 ~296).
FIG. 11 is a diagram showing main parts of a hot water production system 1 according to a third embodiment of the present invention, including a first hot water tank 40, a water supply tank 60, water heaters 11, 12, and 13, and a switching means 290. (Switching valves 291 to 296).

As shown in FIG. 11, in this embodiment, a first hot water supply line L1 and a first hot water return constituting a first circulation line connecting between the water heaters 11, 12, 13 and the first hot water tank 40 are used. line L1R, a second hot water supply line L21 and a second hot water return line L21R that constitute a second circulation line that connects the water heaters 11, 12, 13 and the water supply tank 60.
The first hot water supply line L1, the first hot water supply return line L1R, the second hot water supply line L21, and the second hot water supply return line L21R are connected to the plurality of water heaters 11, 12, and 13, respectively, as shown in FIG. It branches in the middle.

A switching valve 291 is provided on the hot water outlet side of the water heater 11 (the side from which hot water is dispensed). Further, a switching valve 292 is provided on the hot water inlet side of the water heater 11 (the side to which hot water returns). By controlling the pair of switching valves 291 and 292, a connected state in which the stored water W1 circulates between the water heater 11 and the first hot water tank 40 and a state in which the stored water W1 circulates between the water heater 11 and the water supply tank 60 can be established. The connection state in which W21 circulates can be switched. A connection in which stored water W1 circulates between the water heater 11 and the first hot water tank 40 when the switching valve 291 is switched to the first hot water supply line L1 side and the switching valve 292 is switched to the first hot water return line L1R side. state. When the switching valve 291 is switched to the second hot water supply line L21 side and the switching valve 292 is switched to the second hot water supply return line L21R side, a connection state is established in which the stored water W21 circulates between the water heater 11 and the water supply tank 60. Become.

Similarly, for the water heater 12, by controlling the pair of switching valves 293 and 294, the connection state in which the stored water W1 circulates between the water heater 12 and the first hot water tank 40, and the connection state between the water heater 12 and the water supply tank are established. The connection state in which the stored water W21 circulates between 60 and 60 can be switched.
Similarly, for the water heater 13, by controlling the pair of switching valves 295 and 296, the connection state in which the stored water W1 circulates between the water heater 13 and the first hot water tank 40, and the connection state between the water heater 13 and the water supply tank are established. The connection state in which the stored water W21 circulates between 60 and 60 can be switched.

Next, specific control contents of the switching means 290 will be explained with reference to FIGS. 11 and 12.
The first hot water storage control section 140 controls the switching valves 291 to 296 constituting the switching means 290 based on the detection result of the first temperature sensor 41 provided in the first hot water tank 40.

More specifically, when the water temperature in the first hot water tank 40 rises, the number of water heaters connected to the first hot water tank 40 is decreased by one each time the temperature detected by the first temperature sensor 41 exceeds the temperature threshold by one step. At the same time, the switching means 290 is controlled to increase the number of water heaters connected to the water tank 60 one by one.

In the following, the first target hot water storage temperature, which is the target hot water storage temperature in the first hot water tank 40, is set to 70°C, and the temperature threshold for executing the number control is set to at least 50°C or 60°C. An example will be explained.

When the temperature rises, if the temperature detected by the first temperature sensor 41 is 50° C. or lower, the connected state is such that the stored water W1 circulates between all three water heaters 11, 12, 13 and the first hot water tank 40. The switching valves 291 to 296 are controlled so that.

Next, when the temperature rises and the temperature detected by the first temperature sensor 41 exceeds 50°C, only one of the three water heaters is connected to the water tank 60 so that the stored water W21 circulates. , controls the switching means 290.
For example, the switching valves 295 and 296 are controlled so that only the third water heater 13 is in a connected state in which the stored water W21 circulates between it and the water supply tank 60. At this time, the first water heater 11 and the second water heater 12 continue to circulate the stored water W1 between them and the first hot water tank 40.

Next, when the temperature further rises and the temperature detected by the first temperature sensor 41 exceeds 60°C, two of the three water heaters are connected to the water tank 60 in which the stored water W21 circulates. Thus, the switching means 290 is controlled.
For example, in addition to the third water heater 13, the switching valves 293 and 294 are controlled so that the second water heater 12 is connected to the water supply tank 60 so that the stored water W21 circulates therebetween. At this time, the first water heater 11 continues to circulate the stored water W1 between the first hot water tank 40 and the first hot water tank 40.

Then, even when the temperature further rises and the temperature detected by the first temperature sensor 41 reaches 70° C., which is the first target hot water storage temperature, the system continues to maintain the temperature near the first target hot water storage temperature. Only one water heater circulates the stored water W1 between it and the first hot water tank 40.
Note that when the temperature reaches the vicinity of the first target hot water storage temperature, the hot water supply control unit 110 may continue to perform constant hot water supply temperature control; Feedback control may also be performed.

If the temperature further rises and the temperature detected by the first temperature sensor 41 exceeds 75°C, all three water heaters enter a connected state in which the stored water W21 circulates between them and the water supply tank 60. The switching valves 291 to 296 are controlled accordingly. As a result, the stored water W1 is not circulating between the water heater and the first hot water tank 40.

Next, a description will be given of the time when the temperature decreases.
When the temperature in the first hot water tank 40 decreases, the number of water heaters connected to the first hot water tank 40 is increased by one each time the temperature detected by the first temperature sensor 41 falls below the temperature threshold by one level, and at the same time The switching means 290 is controlled to reduce the number of water heaters connected to the tank 60 one by one.
For example, if the temperature detected by the first temperature sensor 41 exceeds 75°C and then falls below 70°C, only one water heater becomes connected to the first hot water tank 40 in which the stored water W1 circulates. Therefore, the switching means 290 is switched. Next, when the temperature detected by the first temperature sensor 41 falls below 60°C, the switching means 290 is activated so that the two water heaters are connected to each other so that the stored water W1 circulates between them and the first hot water tank 40. Switch. Next, when the temperature detected by the first temperature sensor 41 falls below 50°C, the switching means 290 is activated so that all three water heaters are connected to the first hot water tank 40 so that the stored water W1 circulates. Switch. In this control, when the number of water heaters connected to the first hot water tank 40 is increased by one, the number of water heaters connected to the water tank 60 is decreased by one.

Note that a state confirmation time may be provided when switching the switching means 290 according to the temperature detected by the first temperature sensor 41. That is, when the temperature rises, if it is determined that the state in which the detected temperature of the first temperature sensor 41 exceeds a predetermined temperature threshold continues for a first predetermined period of time, the switching means 290 is configured to be controlled to be switched. Good too. In addition, when it is determined that the temperature detected by the first temperature sensor 41 continues to be below a predetermined temperature threshold for a second predetermined period of time during a temperature drop, the switching means 290 may be switched. Good too.
With such control, the switching means 290 can perform switching control based on the confirmation time that the detected temperature continues to decrease or the detected temperature continues to increase. Therefore, when the detected temperature of the first temperature sensor 41 fluctuates around the temperature threshold value, it is possible to prevent a situation in which the switching control by the switching means 290 is frequently executed.
Preferably, the set value of the status confirmation time is adjustable. The set value of the status confirmation time can be adjusted manually or automatically, and can be set to a value larger than 0. Note that the state confirmation time is measured using an internal timer or the like of the control unit 100.

Note that the first hot water storage control unit 140 does not make the control state of the switching means 290 in a predetermined temperature range approximately the same as shown in FIG. 14, but shifts it by one step when the temperature rises and when the temperature falls. Good too.
For example, a case will be described in which the first target hot water storage temperature in the first hot water tank 40 is set to 70°C to 75°C.
At this time, when the temperature rises, if the temperature detected by the first temperature sensor 41 is 60°C or less, the stored water W1 is flowing between all three water heaters 11, 12, 13 and the first hot water tank 40. The switching valves 291 to 296 are controlled to achieve a circulating connection state. When the temperature exceeds 60° C., the switching means 290 is controlled so that only one of the three water heaters is connected to the water supply tank 60 so that the stored water W21 circulates therebetween. When the temperature exceeds 70° C., the switching means 290 is controlled so that two of the three water heaters are connected to the water supply tank 60 so that the stored water W21 circulates therebetween.
When the temperature exceeds 75° C., the switching valves 291 to 296 are controlled so that all three water heaters are connected to the water supply tank 60 so that the stored water W21 circulates therebetween.

On the other hand, when the temperature falls, if the temperature detected by the first temperature sensor 41 falls below 70°C, only one water heater is connected to the first hot water tank 40 so that the stored water W1 circulates. , switches the switching means 290. When the temperature drops below 60° C., the switching means 290 is switched so that the two water heaters are connected to each other so that the stored water W1 circulates between them and the first hot water tank 40. When the temperature drops below 50° C., the switching means 290 is switched so that all three water heaters are connected to the first hot water tank 40 so that the stored water W1 circulates therebetween.
Even with such control, when the temperature detected by the first temperature sensor 41 fluctuates around the temperature threshold, it is possible to prevent a situation where the water heater is frequently started and stopped.

Regarding the control of the hot water supply temperature of the water heater, basically the hot water supply temperature is constant control as in the first embodiment, but feedback control based on the first temperature sensor 41 may be performed for part of the control.

The water supply tank 60 that circulates stored water between the water heater and the water heater stores service water to be supplied to the water heater (makeup water to be supplied in the first hot water tank 40) and/or supply water to be supplied to the steam boiler device 30. However, other water supply tanks may be used as long as they store water that is preferably heated.

Thereby, hot water production can be performed by switching between the first hot water tank 40 and the water supply tank 60 depending on necessity. In addition, by being switchable, it becomes possible to continue the operation of the heat pump type water heaters 11, 12, and 13 as much as possible, which solves the problem of low-temperature water supply at the initial stage of restarting the operation of the heat pump type water heaters 11, 12, and 13. be able to.

Note that a third temperature sensor is provided to detect the temperature of the water stored in the water tank 60, and when the temperature detected by the third temperature sensor reaches the heating stop temperature, the first hot water storage control unit 140 stops the hot water from being supplied to the water tank 60. Control may be performed to stop the water heater.
Thereafter, when the temperature detected by the third temperature sensor falls to the heating start temperature, the water heater that has stopped supplying hot water to the water tank 60 is restarted, and control is executed to restart the circulation between the water tank 60 and the water heater. You may go.
Alternatively, a third water level sensor is provided to detect the water level of the water stored in the water supply tank 60, and when the detected water level of the third water level sensor reaches the heating start water level, the operation of the water heater that has stopped supplying hot water to the water supply tank 60 is stopped. Control may be performed to resume the circulation between the water supply tank 60 and the water heater.
Thereby, the temperature of the stored water in the water supply tank can be appropriately managed.

According to the hot water production system 1 of the present embodiment described above, in addition to (1) to (10), the following effects are achieved.

(11) The hot water production system 1 of the present embodiment includes a water tank 60 that stores water to be supplied to the water heaters 11, 12, 13 and/or water to be supplied to the steam boiler device 30, and switching means 290 for switching the target of circulation heating to the stored water W1 of the first hot water tank 40 or the stored water W21 of the water supply tank 60.
Thereby, hot water production can be performed by switching between the first hot water tank 40 and the water supply tank 60 depending on necessity. Furthermore, by being switchable, it becomes possible to continue the operation of the heat pump as much as possible, and it is possible to solve the problem of low-temperature water supply at the initial stage of restarting the operation of the heat pump.

(12) The hot water production system 1 of the present embodiment includes a first temperature sensor 41 that detects the temperature of the hot water W1 in the first hot water tank 40, and the first heating means 2 includes a plurality of water heaters 11, 12. , 13, and the first hot water tank 40 is set with multiple temperature thresholds for changing the number of connected water heaters 11, 12, 13. Each time the temperature detected by the first temperature sensor 41 falls below the temperature threshold by one step, the number of water heaters 11, 12, 13 connected to the first hot water tank 40 is increased by one, and at the same time, the number of water heaters 11, 12 connected to the water tank 60 is increased by one. . The switching means 290 is configured to decrease the number of water heaters 11, 12, 13 connected to one hot water tank 40 one by one, and at the same time increase the number of water heaters 11, 12, 13 connected to one water tank 60 one by one. Control.
Thereby, hot water production can be performed by switching to the first hot water tank 40 or the water supply tank 260 according to necessity. Moreover, by controlling the switching means 290, it becomes possible to continue the operation of the heat pump as much as possible, and it is possible to solve the problem of low-temperature water supply at the initial stage of restarting the operation of the heat pump.

(13) The hot water production system 1 of the present embodiment includes a third temperature sensor that detects the temperature of the water stored in the water supply tank 60, and when the detected temperature of the third temperature sensor reaches the heating stop temperature, the water supply tank 60 Stop the water heater that is supplying hot water.
Thereby, the temperature of the stored water in the water supply tank 60 can be appropriately managed.

Although preferred embodiments of the hot water production system of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate. It is also possible to combine multiple embodiments.

1...Hot water production system 2...First heating means 3...Second heating means 10...Heat pump hot water supply system 11...First heat pump water heater 12...Second heat pump water heater 13...Third heat pump water heater 14 , 15, 16... Hot water supply temperature sensor 30... Steam boiler device 31... Once-through boiler 40... First hot water tank 41... First temperature sensor 42... First water level sensor 421... First electrode rod 422... Second electrode rod 423... Three electrode rods 424...Fourth electrode rod 425...Fifth electrode rod 51...Steam header 52...Connection line 53...Steam supply line 54...Steam supply valve for temperature rise 55...Pressure gauge 60...Water supply tank 62...Makeup water valve 75 …Preheating heat exchanger 76…Preheating steam supply valve 80…Switching means 81, 82, 83…Switching valve 90…Heat pump circuit 91…Refrigerant compressor 92…Condenser 93…Expansion valve 94…Evaporator 100…Control unit 110...Hot water supply control section 120...Boiler control section 130...Steam supply control section 140...First hot water storage control section 150...Second hot water storage control section 240...Second hot water tank 241...Second temperature sensor 242...Second water level sensor 243... Hot water pump 290...Switching means L1...First hot water supply line L1R...First hot water supply return line L2...Steam supply line for temperature rise L4...Boiler water supply line L5...Makeup water line L6...Hot water outlet line L7...Refrigerant circulation line L8...Heat source Water supply line L10...Preheating steam supply line L16...Hot water delivery line L21...Second hot water supply line L21R...Second hot water supply return line W1...Water (hot water, stored water)
W2…Hot water (reserved water)
W5…Make-up water (service water, cold water)
W6...Hot water W21...Stored water S...Steam R...Refrigerant WL1, WL2...Water level

Claims (13)

a first heating means for heating the water to a target hot water supply temperature while circulating the water to the heat pump water heater;
The water heated to the target hot water supply temperature by the first heating means is heated by direct heat exchange with steam generated by a steam boiler to raise the temperature to a target hot water outlet temperature set higher than the target hot water supply temperature. 2 heating means;
Control means for controlling the first heating means and the second heating means,
In the hot water production system, the control means adjusts output sharing between the water heater and the steam boiler according to the set target hot water temperature. The second heating means includes:
a steam header that collects steam generated in the steam boiler;
a heating steam supply valve that adjusts the amount of steam supplied from the steam header,
The control means includes:
a boiler control unit that controls the steam boiler so that the header pressure of the steam header becomes a target steam pressure;
The hot water production system according to claim 1, further comprising a steam supply control unit that controls the temperature raising steam supply valve so that the hot water discharged from the second heating means has the set target hot water discharge temperature. . The first heating means includes:
a first hot water tank that is supplied with unheated service water and stores hot water generated by circulating and heating the service water through the water heater;
a circulation line that circulates water between the water heater and the first hot water tank;
A hot water supply temperature sensor that detects the hot water supply temperature of the hot water generated by the water heater,
The second heating means includes:
a heating steam supply line that supplies steam generated by the steam boiler to hot water generated by the water heater;
a temperature-raising steam supply valve provided in the temperature-raising steam supply line;
a second temperature sensor that detects the temperature of the hot water after the steam is supplied;
Equipped with
The control means includes:
The water heater is controlled so that the temperature detected by the hot water temperature sensor becomes the target hot water supply temperature, and the opening degree of the heating steam supply valve is controlled so that the temperature detected by the second temperature sensor becomes the target hot water supply temperature. The hot water production system according to claim 1, wherein the hot water production system controls: The second heating means includes:
a second hot water tank to which hot water is supplied from the first hot water tank;
The heating steam supply line supplies the second hot water tank with the steam generated in the steam boiler,
The hot water production system according to claim 3, wherein the second temperature sensor detects the temperature of the hot water in the second hot water tank. The first heating means includes:
comprising a first temperature sensor that detects the temperature of hot water in the first hot water tank;
The control means includes:
The hot water production system according to claim 3 or 4, wherein execution and stop of circulation of water via the circulation line are switched based on the temperature detected by the first temperature sensor. The first heating means includes:
a first water level sensor that detects the water level in the first hot water tank;
a makeup water line that supplies water to the first hot water tank;
A make-up water valve provided in the make-up water line,
The control means includes:
The hot water production system according to any one of claims 3 to 5, wherein the make-up water valve is opened when the detected water level of the first water level sensor falls below a set water level. a preheating heat exchanger that indirectly exchanges heat between water and steam flowing through the make-up water line;
a preheating steam supply line that supplies steam generated in the steam boiler to the preheating heat exchanger;
A preheating steam supply valve provided in the preheating steam supply line,
The control means includes:
The hot water production system according to claim 6, wherein the preheating steam supply valve is opened when the make-up water valve is opened. a hot water pump installed in a hot water delivery line connecting the first hot water tank and the second hot water tank;
a second water level sensor that detects the water level of the second hot water tank;
The control means includes:
The hot water production system according to claim 4, wherein the hot water pump is driven when the detected water level of the second water level sensor falls below a set water level. The first heating means includes a first temperature sensor that detects the temperature of hot water in the first hot water tank,
The first heating means includes a plurality of the water heaters,
A plurality of temperature thresholds for changing the number of operating water heaters are set in the first hot water tank,
The control means includes:
When the temperature in the first hot water tank decreases, the number of water heaters in operation is increased by one each time the temperature detected by the first temperature sensor drops by one level below the temperature threshold;
When the temperature in the first hot water tank increases, a number control is performed in which the number of operating water heaters is decreased by one each time the temperature detected by the first temperature sensor exceeds the temperature threshold by one step. 9. The hot water production system according to any one of 4 to 8. a water tank that stores water to be supplied to the water heater and/or water to be supplied to the steam boiler;
The hot water production system according to any one of claims 4 to 8, further comprising a switching means for switching the circulating heating target of the water heater to the water stored in the first hot water tank or the water stored in the water supply tank. The first heating means includes a first temperature sensor that detects the temperature of hot water in the first hot water tank,
The first heating means includes a plurality of the water heaters,
A plurality of temperature thresholds for changing the number of connected water heaters are set in the first hot water tank,
The control means includes:
When the temperature in the first hot water tank decreases, the number of water heaters connected to the first hot water tank is increased by one each time the temperature detected by the first temperature sensor falls below the temperature threshold by one. , controlling the switching means to reduce the number of water heaters connected to the water tank one by one;
When the temperature in the first hot water tank increases, the number of water heaters connected to the first hot water tank is decreased by one each time the temperature detected by the first temperature sensor exceeds the temperature threshold by one step. 11. The hot water production system according to claim 10, wherein the switching means is controlled to increase the number of water heaters connected to the water supply tank one by one. comprising a third temperature sensor that detects the temperature of the water stored in the water supply tank,
The control means includes:
The hot water production system according to claim 10 or 11, wherein the water heater that is supplying hot water to the water tank is stopped when the temperature detected by the third temperature sensor reaches a heating stop temperature. a first heating step of heating the water to a target hot water supply temperature while circulating the water to the heat pump water heater;
A step in which the water heated to the target hot water supply temperature in the first heating step is heated to a target hot water output temperature set higher than the target hot water supply temperature by directly exchanging heat with steam generated in a steam boiler. 2 heating steps;
A method for producing hot water, in which output sharing between the water heater and the steam boiler is adjusted according to the set target hot water temperature when performing the first heating step and the second heating step.

Images